Oil-soluble aliphatic acid modified high molecular weight mannich condensation products

ABSTRACT

THE THERMAL OXIDATION STABILITY OF ALIPHATIC ACID-MODIFIED HIGH MOLECULAR WEIGHT MANNICH CONDENSATION PRODUCTS, WHICH ARE PREPARED BY REACTING (1) A HIGH MOLECULAR WEIGHT ALKYL-SUBSTITUTED HYDROXY AROMATIC COMPOUND, IN WHICH THE ALKYL-SUBSTITUENT HAS AN AVERAGE MOLECULAR WEIGHT OF FROM ABOUT 600 TO ABOUT 100,000, (2) AN AINE COMPOUND CONTAINING AT LEAST ONE HN&lt; GROUP, (3) AN AMINAN ALIPHATIC ALDEHYDE, AND (4) AN ALIPHATIC ACID CONTAINING AT LEAST SIX CARBON ATOMS, IN THE REACTANT MOLAR RATIO OF 1:0.1-10:1-10:0.014-1.0, RESPECTIVELY, ARE IMPROVED BY REACTING SUCH MODIFIED MANNICH CONDENSATION PRODUCTS WITH FROM ABOUT 2 TO ABOUT 6 MOLES OF AN ALIPHATIC ALDEHYDE PERMOLE OF THE ALKYL-SUBSTITUTED HYDROXY AROMATIC COMPOUND USED IN PREPARING THE MODIFIED MANNICH CONDENSATION PRODUCT. THE PRODUCTS OF THE HEREIN-DESCRIBED INVENTION ARE OIL-SOLUBLE, AND ARE HIGHLY EFFECTIVE ADDITIVES FOR IMPARTING DISPERSANT-DETERGENT PROPERTIES TO LUBRICANT OIL COMPOSITIONS. LUBRICANTS CONTAINING THESE PRODUCTS PROVIDE A HIGH DEGREE OF PROTECTION AGAINST THE DEPOSITION OF SLUDGE AND VARNISH, AND CORROSION WHEN USED AS CRANKCASE LUBRICANT ADDITIVES.

3,787,458 OIL-SOLUBLE ALIPHATIC ACID MODIFIED HIGH MOLECULAR WEIGHTMANNICH CONDENSA- TION PRODUCTS Edmund J. Piasek, Chicago, and Robert E.Karl], Batavia, Ill., assignors to Standard Oil Company, Chicago, Ill.No Drawing. Continuation-impart of application Ser. No. 54,558, July 13,1970. This application Aug. 31, 1970, Ser. No. 68,469

Int. Cl. C09f 7/00 US. Cl. 260-4045 Claims ABSTRACT OF THE DISCLOSUREThe thermal oxidation stability of aliphatic acid-modified highmolecular weight Mannich condensation products, which are prepared byreacting (1) a high molecular weight alkyl-substituted hydroxy aromaticcompound, in which the alkyl-substituent has an average molecular'weight of from about 600 to about 100,000, (2) an amine compoundcontaining at least one HN group, (3) an aliphatic aldehyde, and (4) analiphatic acid containing at least six carbon atoms, in the reactantmolar ratio of 1:0.110:l-10:0.014l.0, respectively, are improved byreacting such modified Mannich condensation products with from about 2to about 6 moles of an aliphatic aldehyde per mole of thealkyl-substituted hydroxy aromatic compound used in preparing themodified Mannich condensation product. The products of theherein-described invention are oil-soluble, and are highly effectiveadditives for imparting dispersant-detergent properties to lubricant oilcompositions. Lubricants containing these products provide a high degreeof protection against the deposition of sludge and varnish, andcorrosion when used as crankcase lubricant additives.

RELATED APPLICATIONS This application isa continuation-in-part of ourcopending application Ser. No. 54,558, filed July 13, 1970.

BACKGROUND OF THE INVENTION This invention relates to improvedlubricating oils and particularly concerns automobile and dieselcrankcase lubricating oil formulations containing a minor amount of anew class of oil-soluble addition agents which improve the performanceof the oil, particularly its dispersant-detergent function thus enablinglubricating oils to provide a high degree of protection of thelubricated parts of internal combustion engines.

Present-day automobile and diesel engines have been designed for higherpower output, lower combustion products emission and longer in-serviceperiods of use of crankcase lubricating oils. These design changes haveresulted in such severe operating conditions as to necessitate devisinghigher efliciency lubricating oils that will, under the increasedseverity of in-service use, afford proper protection against corrosionand the accumulation or deposition of sludge, varnish and resinousmaterials on the surface of engine parts which rapidly acceleratedecrease in both operating efficiency and life of the engine. Theprincipal ingredient of crankcase lubricants is a base lubricating oil,a mixture of hydrocarbons derived from petroleum. Even when highlyrefined by removal of deleterious components, such as polymerizablecomponents, acid formers, waxes, etc., a lubricant base oil stillrequires the addition of a number of oil-soluble chemical additives toenable the oil to resist oxidation, deposition of sludge and varnish on,and corrosion of, the lubricated metal parts, and to provide addedlubricity and regulated viscosity change from low to high temperature.

United States Patent O 3,787,458 Patented Jan. 22, 1974 Theseingredients are commonly known as anti-oxidants, dispersant-detergents,pour point dispersants, etc.

Combustion products from the burning of fuel and thermal degradation oflubricating oils and addition agents tend to concentrate in thecrankcase oil with the attendant formation of oil-insolubledeposit-forming products, that either surface coat the engine parts(varnish or lacquerlike films) or settle out on the engine parts asviscous (sludge) deposits or form solid ash-like or carbonaceousdeposits. Any of such deposits can restrict, and even plug, grooves,channels and holes provided for lubricant fiow to the moving surfaces ofthe engine requiring lubrication thus accelerating the wear and thusreducing the efliciency of the engine. In addition, acidic combustionproducts corrode the lubricated metal surfaces. Chemical additives areblended in crankcase oil formulations not only to reduce thermaldecomposition of the oil and addition agents (antioxidants) but also tokeep in suspension (as a dispersant) and to resuspend (as a detergent)insoluble combustion and degradation products as well as to neutralizeacidic products (anti-corrosion agents). A separate additive is usuallyadded for each improvement to be effected.

As performance levels increased and recommended periods between oildrains lengthened for both automobile and railway diesel engines, moreefiicient dispersancy and detergency performance, as well as better acidneutralization and lower ash-forming properties were demanded forlubricating oil formulations. Among additives suggested by the prior artare amine salts, amides, imides, and amidines of polybutenyl-substitutedpolycarboxylic acids and polymeric compounds having pendant orgrafted-on polar groups. Other suggested prior additives arecombinations of alkaline earth metal sulfonates and Mannich condensationproducts of low molecular weight alkyl (C -C substituted hydroxyaromaticcompounds, amine having at least one replaceable hydrogen on a nitrogenand aldehydes; and alkaline earth metal salts of such Mannichcondensation products. These prior art products did not provide thedesired dispersancy-detergency properties and possessed theobjectionable property of forming harmful metal-ash deposits.

Mannich condensation products derived from alkylsubstitutedhydroxyaromatic compounds having a relatively low molecular weight alkylsubstituent, i.e., 2 to 20 carbon atoms in the alkyl substituent andchlorinated 'wax (straight chain) type alkyl-substituents are describedin US. Pat, Nos. 2,403,453; 2,353,491; 2,363,134; 2,459,112; 2,984,550and 3,036,003. However, none of such prior Mannich condensation productsare suitable for use as dispersant-detergent addition agents forpresent-day long drain oil interval in-service use.

One known type (US. Pat. No. 2,363,134) has been prepared by reacting,under Mannich reaction conditions, equimolar quantities of a C -Calkyl-substituted phenol and other hydroxy aromatic compounds, andN,N-di-substituted amine and formaldehyde.

The prior C C alkyl-substituted Mannich condensation products commonlyare prepared by the conventional technique of adding the aliphaticaldehyde to a heated mixture of the alkylhydroxyaromatic and aminereagents, in the presence or absence of a solvent, and then heating theresultant mixture to a temperature between -350 F. until dehydration iscomplete. A solvent such as benzene, toluene, xylene, methanol andothers easily separated from the reaction mixture and light mineraloils, such as those used in blending stocks to prepare lubricating oilformulations in which the product is formed as a mineral oil concentrateare usually used. The water by-product is removed by heating thereaction mixture to a temperature sufficiently high, at

least during the last part of the process, to drive oif the water alone,or as an azeotropic mixture with the aromatic solvent, usually by theaid of an inert stripping gas, such as nitrogen, carbon dioxide, etc.

The neutralized or overbased alkaline earth metal salts (alkaline earthmetal phenates) of those prior low molecular weight Mannich condensationproducts have been suggested for use in providing lubricating oils witha combination of detergent-inhibitor properties in one addition agent.The neutralized alkaline earth metal salts have one equivalent ofalkaline earth metal for each bydroxy group present. The overbased saltshave, for each hydroxy group present, more than one equivalent ofalkaline earth metal in the form of a hydroxy metaloxy, alkoxy metaloxyand even alkaline earth metal carbonate complex with hydroxy metaloxy oneach benzene group as a replacement for the phenol hydroxy group. Asnoted above, said addition agents form objectionable metal ash depositsand have other performance deficiencies.

US. Pat. No. 3,368,972, issued Feb. 13, 1968, describes asdispersant-detergent addition agents for lubricating oils high molecularweight Mannich condensation products from (1) high molecular weightalkyl-substituted hydroxyaromatic compound-s whose alkyl-substituent hasa molecular weight in the range of 600-3000, (2) a compound containingat least one HN group and (3) an aldehyde in the respective molar ratioof 1.0:0.l- :1.0-10.

The high molecular weight Mannich condensation prodacts of U.S. Pat. No.3,368,972 have a drawback in their large-scale preparation and in theirextended service use as lubriant addition agents used under hightemperature conditions such as encountered in diesel engines. In thelarge-scale or plant preparation of such high molecular Weightcondensation products, especially in light mineral oil solvents, theresulting oil concentrate solution of the condensation product eitherhas or develops during storage a haze which is believed to be caused byundissolved or border line soluble by-products which not only aresubstantially incapable of removal by filtration but also severelyrestrict product filtration rate. When used in diesel engine crankcaselubricant oils and subject to high temperature in service use, pistonring groove carbonaceous deposits and skirt varnish tend to build upsulficiently rapidly and prevent desirable long in-service use of suchlubricant oils.

As taught and claimed in our aforesaid co-pending application, both ofthese drawbacks are overcome by modifying the high molecular weightMannich condensation products with an aliphatic acid having at least sixcarbon atoms. While such modification of such Mannich condensationproducts overcomes the aforementioned drawbacks, such modified Mannichproducts do not possess the desired thermal oxidation stability. We havenow discovered that the storage and thermal stability of such aliphaticacid-modified high molecular weight Mannich condensation products areimproved by treating such condensation products with an additionalamount of an aliphatic aldehyde.

BRIEF SUMMARY OF THE INVENTION This invention pertains to a new class ofcompounds useful as multifunctional addition agents for lubricatingoils, particularly such oils used in internal combustion engines inwhich they function as highly efiicient dispersant-detergent andoxidation inhibitor agents.

The new class of compounds which comprise our invention are oil-solublehigh molecular aliphatic acid modified high molecular weight Mannichcondensation products, which are further treated with an aliphaticaldehyde. They can be made by condensing in the usual manner underMannich reaction conditions at a temperature in the range of ISO-325 F.

(1) An alkyl-substituted hydroxyaromatic compound, in which thealkyl-substituent has an average molecular weight of about 600-100,000,preferably a polyalkylphe- 1101 whose polyalkyl substituent is derivedfrom l-monoolefin polymers having an average molecular weight of about850-2500;

(2) An amine containing at least one NH group, preferably an alkylenepolyamine of the formula NHz(A-N)H wherein A is a divalent alkyleneradical having 2 to 6 carbon atoms, and x is an integer from 1 to 10;

(3) An aliphatic aldehyde, preferably formaldehyde or paraformaldehyde;followed by reaction with;

(4) A high molecular weight aliphatic acid before or after filtration;or they can be prepared by using all four reactants at one time underthe general Mannich reaction conditions.

The above resultant modified Mannich condensation product is thentreated with (5) an aliphatic aldehyde in an amount of from about 2 toabout 6 moles of the aldehyde per mole of the alkyl-substituted hydroxycompound used in the preparation of said modified Mannich product.

The foregoing high molecular weight products of this invention arepreferably prepared according to the conventional methods employed forthe preparation of Mannich condensation products, using the first fourabove mentioned reactants in the respective molar ratios of aboutl.0:0.1-l0:1.0l0:0.0l41.0. Suitable condensation procedure involvesadding at a temperature of from room temperature to about 200 F. thealdehyde reagent (3) to a mixture of reagents (1), (2), and (4), above,or such reagents in an easily removed organic solvent, such as benzene,Xylene, or toluene, or in a solvent refined mineral oil; completing thereaction at 300 F.; then slowly adding the additional aldehyde, reactant(5) at 180-300" F. The reaction mass is then heated at an elevatedtemperature of about 275-375 F., preferably with blowing with an inertstripping gas, such as nitrogen, carbon dioxide, etc. until dehydrationis complete.

The preferred additives, according to this invention, are high molecularweight bis-Mannich condensation products formed by reacting 1) 3.850-2500 molecular weight polybutylphenol; (2) an ethylene polyamine;(3) formaldehyde; and (4) an aliphatic acid in the respective molarratio of 1.0:0.7-1.0:1.52.1:0.0l40.62, and treating the resultantmodified Mannich condensation product with 2-4 moles of paraformaldehydeper mole of the polybutylphenol. The preferred aliphatic acid reactantis an acid having 10-20 carbon atoms per carboxylic acid group.

To those skilled in the art, it will be recognized that, in general, thereaction under Mannich condensation conditions, as in other chemicalreactions, does not go to theoretical completion, and some portion ofthe reactants remain unreacted or only partially reacted as co-products.Accordingly, the products of this invention cannot be properly oraccurately characterized with preciseness by chemical structuralformula, but must be characterized as reaction products produced by themethod of preparation.

The high molecular weight products of this invention are effectiveadditives for lubricating oil lubricants, imparting theretodispersant-detergent properties and high temperature oxidationstability, at relatively low concentrations, e.g., 0.05% to about 10% informulated crankcase lubricating oil compositions. Higherconcentrations, e.g., 10% to about 70%, are useful concentrates for thepreparation of such lubricating oil compositions.

EMBODIMENT OF THE INVENTION Representative high molecular weightaliphatic acid modified Mannich condensation products contemplated bythis invention can be prepared from the following representativereactants of the classes before defined.

(1) High molecular weight alkyl-substituted HydroxyaromaticsRepresentative of these high molecular weight alkylsubstitutedhydroxyaromatic compounds are polypropylphenol, polybutylphenol andother polyalkylphenols. These polyalkylphenols may be obtained by thealkylation, in the presence of an alkylating catalyst, such as BF ofphenol with high molecular weight polypropylene, polybutaylene and otherpolyalkylene compounds to give alkyl substituents on the benzene ring ofphenol having an average 600-100,000 fin. Their preparation using a BFphenol catalyst is described and claimed in our copending applicationSer. No. 484,758, filed Sept. 2, 1965, now abandoned.

The 600 Mn and higher Mn alkyl-substituents on the hydroxyaromaticcompounds may be derived from high molecular weight polypropylenes,polybutenes and other polymers of mono-olefins, principallyl-mono-olefins. Also useful are copolymers of mono-olefins with monomerscopolymerizable therewith wherein the copolymer molecule contains atleast 90%, by weight, of mono-olefin units. Specific examples arecopolymers of butenes (butene-1, butene-2 and isobutylene) with monomerscopolymerizable therewith wherein the copolymer molecule contains atleast 90%, by weight, of propylene and butene units, respectively. Saidmonomers copolymerizable with propylene or said butenes include monomerscontaining a small proportion of unreactive polar groups such as chloro,bromo, keto, ether, aldehyde, which do appreciably lower theoil-solubility of the polymer. The co-monomers polymerized withpropylene or said butenes may be aliphatic and can also containnon-aliphatic groups, e.g., styrene, methylstyrene, p-dimethylstyrene,divinyl benzene and the like. From the foregoing limitation placed onthe monomer copolymerized with propylene or said butenes, it isabundantly clear that said polymers and copolymers of propylene and saidbutenes are substantially aliphatic hydrocarbon polymers. Thus theresulting alkylated phenols contain substantially alkyl hydrocarbonsubstituents having fin upward from 600.

In addition to these high molecular weight hydroxyaromatic compoundsothers which may be used include those which have been used to prepareprior low molecular weight Mannich condensation products, e.g., highmolecular weight alkyl-substituted derivatives of resorcinol,hydroquinone, cresol, catechol, xylenol, hydroxy diphenyl, benzylphenol,phenethylphenol, naphthol, tolylnaphthol, among others. Preferred forthe preparation of the aforementioned preferred bis Mannich condensationproducts are the polyalkylphenol reactants, e.g., polypropylphenol andpolybutylphenol whose alkyl group has an average number molecular weightof 6003000, the most preferred being polybutylphenol Whose alkyl grouphas an average number molecular weight of 850-2500.

(2) HN group containing reactants Representative of this class ofreactants are alkylene polyamines, principally polyethylene polyamines.Other representative organic compounds containing at least one HN groupsuitable for use in the preparation of Mannich condensation products arewell known and include the monoand di-amino alkanes and theirsubstituted analogs, e.g., ethylamine and diethanol amine; aromaticdiamines, e.g., phenylene diamine, diamino naphthalenes; heterocyclicamines, e.g., morpholine, pyrrole, pyrrolidine, imidazole,imidazolidine, and piperidine; melamine and their substituted analogs.

Suitable alkylene polyamine reactants include ethylenediamine,diethylene triamine, triethylene tetramine, tetraethylene pentamine,pentaethylene hexamine, hexaethylene hepta-amine, heptaethyleneoctamine, octaethylene nonamine, nonaethylene decamine and decaethyleneundecamine and mixture of such amines having nitrogen contentscorresponding to the alkylene polyamines, in the formula H N(A-NH) H,mentioned before, A is divalent ethylene and x is 1 to 10 of theforegoing formula. Corresponding propylene polyamines such as propylenediamine and di-, tri-, tetra-, penta-propylene tri-, tetra-, pentaandhexaamines are also suitable reactants. The alkylene polyamines areusually obtained by the reaction of ammonia and dihalo alkanes, such asdichloro alkanes. Thus the alkylene polyamines obtained from thereaction of 2 to 11 moles of ammonia with 1 to 10 moles of dichloroalkanes having 2 to 6 carbon atoms and the chlorines on differentcarbons are suitable alkylene polyamine reactants.

ALDEHYDE REACTANTS Representative of this aldehyde class of reactantsfor use in the preparation of the high molecular products of thisinvention include the aliphatic aldehydes such as formaldehyde (also asparaformaldehyde and formalin), acetaldehyde and aldol(b-hydroxybutyraldehyde). We prefer to use formaldehyde,para-formaldehyde or a formaldehyde yielding reactant.

ALIPHATIC ACID REACTANTS The aliphatic acid reactant of this inventionhas a carbon atom content of a total (including the carbon of thecarboxylic acid group) of from about six to about 30 and consists of thealkanoic (saturated) and alkenoic (mono-unsaturated) acids. The upperlimit of the carbon content is restricted only by the largest carbonatom content of such acids available or capable of feasible preparation.Such aliphatic acids can be natural and synthetic mono-, diandtri-carboxylic acids. Suitable natural aliphatic acids are the naturalfatty acids obtainable by known hydrolysis (acid and alkaline) ofvegetable and animal oils and fats and wax esters. Of those naturalacids for the purposes of this invention the preferred acids have from10 to about 20 total carbon atoms per carboxylic acid group. Suitablesynthetic acids can be derived from oxidation of the alcohol moiety ofthe Wax ester where such alcohol moiety has at least six carbon atoms;from the polymerization of unsaturated natural acids having two or threecarbon to carbon double bonds (dimer and trimer acids) and thehydrogenation of residual carbon to carbon double bonds in such polymeracids. For example the polymer acids obtained from oleic acid, uricacid, linoleic acid and linolenic acid and other unsaturated acids; andfrom oxidation or other reactions of polypropenes and polybutenes (e.g.polyisobutenes) which introduce one or more carboxylic acid group on thepolymer chain.

It might be expected that the high molecular weight Mannich productmodified by an unsaturated aliphatic carboxylic acid such as oleic acidor its C unsaturated homolog would have less oxidation stability thanfor example such Mannich products modified by a saturated aliphatic acidsuch as stearic acid. But this, somewhat unexpectedly, is not the case.For example, in a standard oxidation stability test (Union PacificOxidation Test) there are tested oil formulations containing equivalentamounts of high molecular weight Mannich product (a' Pentane insolu-Addltive Acid modifier bles, gms.

Mannich product... None. 1. 5 Do Oleie acid. 2.5 Isostearic acid 3. 0015-9113 mixtures of monounsaturated 3.0

aci s. Do Cit-C1 mixture of saturated acids...-. 2.0

Suitable alkanoic acids having 6 or more total carbon atoms are thoseobtainable from the glycerides: vegetable oils and animal fats and thewax esters by the known hydrolysis or saponification-acidification oracid treatment processing of said oil and fat glycerides and the waxesters (i.e. natural waxes), the oxidation of the monoalcohol obtainablefrom the simple ester of the wax esters and known acid synthesis. Suchsuitable alkanoic acids, i.e. having R groups of 6 to 30 carbon atoms,include caproic acid, caprylic acid, capric acid, hendecylic acid,lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmiticacid, margaric acid, stearic acid, nonadecylic acid, arachidic acid,medullic acid, behenic acid, lignoceric acid, pentacosoic acid, ceroticacid, heptacosoic acid, monocosoic acid, montanic acid, and melissicacid. Many of said alkanoic acids are obtained first in mixtures of two,three or more alkanoic acids of different carbon contents from saidglycerides and wax esters; said mixtures can be used in this inventionin place of a single alkanoic acid reactant. When said mixtures ofalkanoic acids also contain unsaturated acids it is preferred that suchmixture of acids be reduced to a product which is substantially free ofunsaturation.

Suitable alkenoic acids having a total of at least six carbon atomsinclude those from hexenoic, heptenoic, octenoic, etc. acids up to oleic(Cm) and erucic (C acids. Also suitable are the dimer acid of linoleicand its saturated dimer analog; dimer and trimer acids of linolenic acidand the saturated dimer and trimer analogs. Other polymeric acids, e.g.co-dimers of oleic and linoleic or linolenic acids and the saturatedanalogs of those dimer acids are also suitable.

The foregoing, while not an exhaustive listing of all suitable aliphaticacid reactants of the class before defined, will provide adequateguidance for the chemist skilled in this art and also bring to mindother suitable aliphatic acids within the scope before defined.

The following examples are illustrative of preferred embodiments of thepresent invention.

EXAMPLE I 2085 grams (0.61 mole) of a 1600 average molecular weightpolybutyl-substituted phenol (47% polybutylphenol, 53% polybutene anddiluent oil), 765 grams of a solvent-extracted W mineral oil, 109 grams(0.56 mole) tetraethylene pentamine, and 109 grams (0.38 mole) of amodified saturated G -C fatty acid, identified as Emery 896 Fatty Acidby Emery Industries Inc., were admixed and heated to 150 F. 84 ccs.(1.12 moles) of formalin were then rapidly added to the mixture.Thereafter, there were slowly added 168 ccs. (2.24 moles) of formalinover a 1.5 hour period, during which time the reaction temperature wasallowed to rise to 200-220" F. Upon completion of the formaldehydeaddition, the reaction mixture was heated to a temperature of 300320 F.and held at such temperature for 3 hours while blowing with nitrogen ata rate of 2 cubic feet per hour (c.f.h.) At the end of three hours thereaction mass was filtered. The recovered filtrate was clear, had anitrogen content of 1.30%, and a SSU viscosity at 210 F. of 954.

EXAMPLE II Part A.2370 grams (0.73 mole) of a 1526 average molecularweight polybutyl-substituted phenol (49.4% polybutylphenol, 50.6%polybutene and oil), 300 grams of a solvent-extracted 5W mineral oil,128 grams (0.454 mole) oleic acid, and 127 grams (0.672 mole)tetraethylene pentamine were admixed at 150 F., and 100 ccs. (1.344moles) formaldehyde added. The temperature was increased to 300-320" F.while blowing with nitrogen at 2 c.f.h., and maintained at suchtemperature for 2 hours. 489 grams of a solvent-extracted 5W mineral oilwere added to the reaction product.

Part B.To 3200 grams of an oleic acid-modified Mannich condensationproduct prepared as in part A, above,

were added at 300 F. grams (2.8 moles) paraformaldehyde, and grams of asolvent-extracted 5W mineral oil, and the mixture maintained at 300-320F. for 3 hours while blowing with nitrogen at the rate of 2 c.f.h. Thereaction product was then filtered.

Three other batches were prepared as the above, and the four batchescombined. The composite product was crystal clear and had a SSUviscosity at 210 F. of 1028.

The thermal oxidation stability of the aldehyde treated acid-modifiedhigh molecular weight Mannich condensation product is demonstrated bythe so-called Hot Tube Test. This test measures the oxidation andthermal stability of dispersant additives for lubricating oils,particularly automotive crankcase lubricants. In making this test thesubject dispersant is incorporated in a typical crankcase lubricatingoil composition formulation, and the composition subjected to thefollowing test: The oil composition being tested is passed, at the rateof 0.1 cc. per minute downward through a 20 inch, 8 mm. vertical glasstube 6 inches of which are surrounded by a furnace and heated at 495 F.for 100 minutes, while air at the rate of 20 cos. per minute is passeddownwardly through the tube. At the end of the 100 minute test periodthe tube is cooled and rinsed with hexane, and the appearance of thetube evaluated as to varnish area and intensity. A prefect tube is rated10A, where the numerical value refers to the varnish in the heatedportion of the tube, and the letter rating refers to the varnish formedin the cool zone of the tube below the furnace. The lower the numericalrating and the higher the letter rating, the poorer is the oxidation andthermal stability of the dispersant.

The data in Table I, below, were obtained by subjecting the followinglubricating oil formulations to the above Hot Tube Test:

Sample A Percent (vol.)

Unmodified Mannich condensation product 1 4.1 Overbased sulfonate 2.0Zinc dialkyl dithiophosphate 1.1 Solvent-extracted 10W mineral oil 70.0Solvent-extracted 5W mineral oil 22.8

1 This Mannich condensation product was prepared by mixing together 260grams (0.073 mole) of a 1600 average molecular weightpolybutyl-substituted phenol (42% polybuty1- phenol, 58% polybutene andoil), 39 grams of a solventextracted 5W mineral oil, 13 grams (0.067mole) tetraethylene pentamine, and the mixture heated to B2, 10 cos.(0.134 mole) formalin were then added, and the mixture reacted at300-320 F. for 3 hours while blowing with nitrogen at the rate of 1c.f.h. At the end of the reaction period the product wfarizgtered. Thefiltrate had a SSU viscosity at 210 F. o

TABLE I Sample: Hot tube rating A B 8.20 C 8.0B

The letter rating B m the above test indicates that the aldehyde treatedacid-modified Mannich condensation product (sample C), exhibits betterthermal oxidation stability than the acid-modified Mannich product(sample B), which had a letter rating of C.

As noted hereinbefore, the products of the present invention are usefuladdition agents for lubricating oils. Such oils can be any normallyliquid oleaginous lubricants, such as hydrocarbon oils, both natural,i.e., petroleum oils, and synthetic lubricating oils, for example, thoseobtained by the polymerization of olefins, as well as syntheticlubricating oils of the alkylene oxide type, and the polycarboxylic acidester type, such as the oil-soluble esters of adipic acid, sebacic acid,azelaic acid, etc.

Lubricating oil compositions containing the aldehyde treatedacid-modified Mannich condensation products of the present invention,may also contain other additives such as for example, VI improvers, rustinhibitors, oiliness agents, pour point depressors, etc.

Percentages given herein and in the appended claims are weightpercentages unless otherwise stated.

Although the present invention has been described with reference tospecific preferred embodiments thereof, the invention is not to belimited thereto, but includes within its scope such modifications andvariations as come within the scope and spirit of the appended claims.

We claim:

1. An oil-soluble aliphatic acid-modified high moleclar weight Mannichcondensation product prepared by the process comprising (A) reacting ata temperature of from about 150 F. to 325 F.:

(a) a high molecular weight alkyl-substituted phenol wherein the alkylsubstituent has an average molecular weight of from about 600 to about100,000;

(b) an alkylene polyamine;

() formaldehyde; and

(d) a higher aliphatic acid containing to 30 carbon atoms, saidreactants (a), (b), (c), and (d) being used in the molar ratios of1.0:0.110:1.0- 10:0.014-0, respectively, (B) then slowly adding to theresultant foregoing product of (A) at a temperature in the range of180300 F.;

(e) additional formaldehyde in the molar ratio of from about 2 to about6 moles thereof per mole of said reactant (a), and (C) increasing thetemperature of the resultant reaction mass to from about 275 F. to about375 F. while blowing with an inert stripping gas to dehydrate theresultant product.

2. The oil-soluble aliphatic acid-modified high molecular weight Mannichcondensation product of claim 1, wherein the high molecular weightalkyl-substituted hydroxyaromatic compound is a polyalkyl-substitutedphenol, wherein the polyalkyl-substituted has a molecular weight of fromabout 600 to about 3,000.

3. The oil-soluble aliphatic acid-modified high molecular weight Mannichcondensation product of claim 2 wherein the alkylene polyamine istetraethylene pentamine.

4. The oil soluble aliphatic acid-modified high molecular weight Mannichcondensation product of claim 2, wherein the additional aldehyde (e) isparaformaldehyde.

5. The oil-soluble aliphatic acid-modified high molecular weight Mannichcondensation product of claim 3, wherein the aliphatic acid is oleicacid.

6. An oil-soluble aliphatic acid modified high molecular weight Mannichcondensation product prepared by the process comprising, (A) reacting ata temperature of from 150 to 325 F.:

(a) a high molecular weight alkyl-substituted phenol wherein thealkyl-substituent has an average molecular weight of from about 600 toabout 3,000;

(b) an alkylene polyamine;

(c) formaldehyde; and

(d) a higher aliphatic acid containing 10 to 30 carbon atoms, saidreactants (a), (b), (c) and (d) being used in molar ratios of1.0:0.110:l.0-10:0.0141.0, respectively, (B) then slowly adding to theresultant foregoing product of (A) to a temperature in the range of180-300 F.;

(e) additional formaldehyde in the molar ratio of from about 2 to about6 moles thereof per mole of said reactant (a), and (C) increasing thetemperature of the resultant reaction mass to from about 275 F. to about375 F. while blowing with an inert stripping gas to dehydrate theresultant product.

7. The oil-soluble aliphatic acid modified Mannich condensation productof claim 6, wherein the alkyl-substituted phenol (a) is selected fromthe group consisting of polypropylphenol and a polybutylphenol in whichthe polypropyl and the polybutyl substituents have average molecularweight of from about 600 to about 3,000, the amine reactant (b) has theformula wherein at is an integer from 1 to 10, aldehyde (0) is formalin,the aliphatic acid (d) is a fatty acid having from about 10 to about 20total carbon atoms per carboxylic acid group, and the additionalaldehyde (e) is paraformaldehyde.

8. The oil-soluble aliphatic acid modified high molecu lar weightMannich condensation product of claim 6, wherein the alkyl-substitutedphenol is a polybutylphenol (a) in which the polybutyl substituent hasan average molecular weight of about 1,500, the alkylene polyamine (b)is tetraethylene 'pentarnine, aldehyde (c) in formalin, the aliphaticacid (d) is oleic acid, and the additional aldehyde (e) isparaformaldehyde.

9. A method of preparing the oil-soluble acid-modified high molecularweight Mannich product of claim 1 as solute in the presence ofhydrocarbon diluent consisting essentially of aliphatic hydrocarbon of600-100,000 average molecular Weight and mineral lubricating oil whichcomprises reacting at a temperature in the range of 325 F. and in thepresence of said diluent said reactants (a), (b), (c) and (d) in therespective molar ratio of 1.0:0.11.0:1.010:0.0l41.0 and then furtherreacting (e) 26 moles additional formaldehyde per mole of reactant (a)at a temperature in the range of 27 5-37 5 F. while blowing with inertstripping gas until the resultant product is dehydrated, wherein theamount of said diluent used provides 10-70 weight percent of saidMannich product as solute.

10. The method of claim 9 wherein the hydrocarbon diluent is butenepolymer derived hydrocarbon of about 1500 number average molecularweight and SAE-SW oil, reactant (a) is about 1500 number averagemolecular weight polybutyl-substituted phenol, (b) is tetraethylenepentamine, (c) is formaldehyde, (d) is oleic acid and (e) isparaformaldehyde and wherein the amount of said diluent provides 40weight percent of said Mannich product as solute.

References Cited UNITED STATES PATENTS 3,326,801 6/ 1967 Schlobohm etal. 260-4045 3,368,972 2/1968 Otto 252-515 R 3,442,808 5/1969 Traise etal 252-515 A 3,216,936 11/1965 Le Suer 260-4045 2,276,309 3/1942 Hummelet al. 260-4045 3,280,970 10/ 1966 Cizek 260-4045 3,036,003 5/1962Verdol 252-515 R 2,992,230 7/1962 Lescisin 260-4045 2,765,325 10/1956Niederhauser 260-4045 GLENNON H. HOLLRAH, Primary Examiner US. Cl. X.R.

252-515, 51.5 A; 260-247.7, 249.6, 293.89, 293.9, 309, 309.7, 326.5,326.8, 404, 561 R, 561 N, 562 R, 562 P -UN1TED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent N9. 317 7 5 Dated JQ J Y 2, 197

Inventor) Edmuhd J. Piasek and. Robert E. Karll It is certified thaterror appears in the abov-idgntified p'aten't and that said LettersPatent are hereby cprrect'ed as shown below:

Column 5, ,Lin'h9 bis Mannich should be bis -Mannich Column 8, Luis-A'-c.f.h. should be c.F.H

c.f.h.- shouldbe C.-F.,H. 1

Column 8, Line #7 Column 9, Li e'fe' f, 0' should. be 1.0

(SEAL) Attest: I I I I McCOY M. GIBS'O N JIR. 4 c. MARSHALL DIA NNAttesting Officer I Commissioner of Patents

